The invention relates to a method for controlling rock drilling, wherein a percussion device belonging to a rock drill machine delivers impact pulses to rock through a tool and wherein the rock drill machine is simultaneously pushed against the rock by means of a feed actuator, the method comprising: feeding a pressure medium to the feed actuator along at least one feed channel; feeding the pressure medium to the percussion device along at least one percussion pressure channel; determining a penetration rate; and adjusting at least a percussion pressure on the basis of the penetration rate.
The invention further relates to a rock drilling arrangement comprising: a rock drill machine including a percussion device arranged to generate impact pulses to a tool to be connected to the rock drill machine; a feed beam whereon the rock drill machine has been arranged; a feed actuator enabling the rock drill machine to be moved in the longitudinal direction of the feed beam; a pressure medium system comprising: at least one pressure source; at least one pressure medium channel leading to the percussion device; at least one feed channel connected to the feed actuator; and means for adjusting a percussion pressure,
When holes are drilled into rock, the drilling conditions may vary in several ways. The rock may include voids and cracks, and rock layers having different hardness, which is why drilling parameters should be adjusted according to the resistance opposed to the drilling bit.
Conventionally, an operator controls the operation of a rock drill machine on the basis of his or her personal experience. The operator sets certain drilling parameters on the basis of the presumed rock characteristics. During drilling, the operator checks the rotation and monitors the progress of the drilling. When necessary, he changes the feed force and/or the percussion power of the percussion device to suit a particular type of rock, thus trying to achieve a fast but still smooth drilling process. In practice, the operator is able to adjust one only drilling parameter and control its influence on the drilling process in several seconds or tens of seconds. When the quality of rock or the drilling characteristics thereof changes rapidly, even a qualified operator cannot adapt the drilling parameters quickly enough to suit the rock. It is thus obvious that the operator cannot ensure a good tool life if drilling conditions vary rapidly. Furthermore, it is practically impossible even for a qualified operator to monitor and control the operation of the rock drilling machine during an entire working shift such that the drilling progresses efficiently at every moment, simultaneously taking into account the stresses the tool is subjected to.